Unity and Variety, Tension & Release
Two very important factors in music, as well as most other art forms, are the creation of tension and release. Let’s look at how tension and release can be created by combining unity and variety.
Unity does not necessarily imply monotony and variety does not necessarily imply interest.
Limited range of pitch
|Lack of repetition
Wide range of pitch
A good composer knows when to introduce contrasting material at the right time to release that tension. (For example by repeating an idea until the point where the listener is about to get bored). Tension can also be created by the lack of repetition, by the use of many contrasting and changing musical ideas and then released by the sudden appearance of repeated or static material.
On the other hand we don’t have to assume that it’s wrong to keep repeating a melodic phrase beyond the stage where it may be considered boring. There are many instances where you may wish to create a
hypnotic or soothing effect. In this case beware that there may be a tension created by constant repetition that you don’t want, so it may be worth introducing some very subtle and gradual change either in the harmony, tone colour, rhythm or melodic content. Imagine the calming effect of listening to the gentle rhythm of waves on a seashore. This rhythm is not exactly constant metronomically, neither is each wave identical. There may be changes in the background sounds (seagulls or children playing).
Sometimes variety can be created by using unexpected intervals. This can create interest but if it is overdone the interest ceases to exist as the surprise element is replaced with predictability. There’s a very fine balance required in the use of such devices, which is often purely subjective, and in most cases subconscious on the part of the composer. You may decide to use a
wrong note. For instance most people would consider a Db on a C major chord to be an unpleasant dissonance (as opposed to a pleasant or useful dissonance). However if it is
set up or
prepared (for example by a repeated phrase where that note does fit the harmony and the C major is then introduced) then the dissonance can make sense and become useful. One may also want to look at where the melody had come from and where it was leading.
In previous centuries harmonies which we accept as pleasing used to thought of as unpleasant dissonances, for example a suspended fourth on a chord had to be
prepared by stating the note prior to the chord. This rule though it does have some use is largely irrelevant in the music written today. It is perhaps better to think of dissonance not as an unpleasant sound but as a harmony that possesses some tension or need to go somewhere, whether to another dissonance or a consonance (a harmony that sounds “at rest” ).